Using these D'Addario EJ20 guitar strings is easy. First, remove the old strings from your guitar one by one. Then, thread the new strings through the bridge and the tuning pegs, and tune them to the correct pitch. When you're playing, be gentle with the strings to avoid breakage. For maintenance, wipe the strings with a clean cloth after each use to remove sweat and dirt. Store your guitar in a dry place to prevent the strings from rusting. If you notice the tone getting dull, it might be time to replace the strings.